Here is something interesting. I am in the middle of trimming one of my own horses, Allie. About six months ago she had a knock to her coronary band that caused a wound that wasn't too major, so I thought nothing of it. Today while trimming I pulled my knife over it gently and the 'hoof' that seemed to be plugging it popped out. I think it was actually a piece of wood that had gotten stuck, or possibly it had been the cause of the injury and had not quite been removed by the body. Anyway, behind it was minor infection, but quite deep. I had to take my small knife and clear it out. Then I made the hole bigger so nothing else gets clogged in there.
It should be ok, but it is worrying as it is quite deep. There is no reason to pack it, I will just keep it clean and might give it an apple cider scrub every other day or so.
I won't make any changes to her work load, as her hoof wall is very strong and thick. I will keep the walls rolled and take care as it grows out.